rcu: Use WRITE_ONCE in RCU_INIT_POINTER

For the paranoid amongst us GCC would be in its right to use byte stores
to write our NULL value, tell it not to do that.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index def6d45ad61c02ef79adfb87d08efbb148976fbd..c63428c1ed8a785a06661ce3fbead937ad88d756 100644 (file)
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -995,7 +995,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
 #define RCU_INIT_POINTER(p, v) \
        do { \
                rcu_dereference_sparse(p, __rcu); \
-               p = RCU_INITIALIZER(v); \
+               WRITE_ONCE(p, RCU_INITIALIZER(v)); \
        } while (0)
 
 /**